In producing petroleum and other useful fluids from production walls, it is generally known to provide a submergible pumping system for raising the fluids collected in a well. Production fluids enter a wellbore via. perforations formed in a well casing adjacent a production formation. Fluids contained in the formation collect in the wellbore and may be raised by the submergible pumping system to a collection point above the earth's surface.
In a conventional bottom intake electric submergible pumping system, the system includes several components, such as a submergible electrical motor that supplies energy to a submergible pump. The system may further include a motor protector for isolating the motor from well fluids. A motor connector may also be used to provide a connection between the electrical motor and an electrical power supply. These and other components may be combined in the overall submergible pumping system.
Generally, the submergible pump and pump intake are disposed beneath the motor and protector. This system is lowered into a wellbore casing until it is submerged or at least partially submerged in the wellbore fluids. Somewhere between the pump intake and the pump discharge, the submergible pumping system must be sealed with respect to the wellbore casing such that production fluids, e.g., petroleum, may be pumped into the annulus formed about the submergible pumping system within the wellbore casing. The production fluid is continually pumped into this annulus such that the production fluid rises to the top of the wellbore casing at or above the earth's surface. The entire submergible pumping system is deployed in the wellbore casing by, for instance, a cable or coil tubing so that the system may later be retrieved.
Current bottom intake electrical submergible pumping systems basically are set at a predetermined location within the wellbore casing, and that location cannot be changed without substantial additional steps beyond simply lifting or moving the submergible pumping system. For example, in some applications, a permanent packer is installed in the wellbore, and the submergible pumping system stings into the packer. In other applications, a liner having a seating shoe is run inside the production casing. The bottom intake electric submergible pumping system engages and seals against this seating shoe. In either of these applications, movement of the pumping system to another location along the wellbore casing requires that another permanent packer be set or the liner and seating shoe be moved in an operation separate from movement of the submergible pumping system. Additionally, servicing of the submergible pumping system and packer/seating shoe requires at least two trips out of the well, adding many hours of down time.
Previously, an attempt was made to combine a submergible pumping system with an integral packer. In the subject system, the packer is set against the well casing upon initiation of the pump via the electric motor. However, this is problematic, because most wellbore fluid pumping applications require that the pumping system be set in place within the wellbore casing prior to pump start-up.
It would be advantageous to utilize a packer mandrel connected within the string of components of the submergible pumping system that could accommodate a packer of the type that could be set independently of initiation of pumping.